One dichotomy between the communication protocols is that the message can be either continuous [1]} or discrete [2]}. It is desirable that agents communicate using discrete messages, as it is more suitable for channels with limited bandwidth. Discrete representation allows us to greatly reduce the amount of information broadcast by the agents, which can be essential for deploying communication methods in the real world. Note that even with a restricted message channel, discrete messages can greatly enhance the performance of the agents [2]}.
